An inspection or a test of electric characteristics of a packaged or molded semiconductor device, in particular, an integrated circuit (IC), is generally conducted by utilizing an inspection socket, i.e., a test socket for removably mounting a semiconductor device as an auxiliary unit for inspection.
In one of electrical connecting apparatus of this type, a plurality of probes, i.e., contacts bent substantially in J-shape are used (Japanese Patent Appln. Public Disclosure (KOKAI) No. 2003-123874).
In this prior art, each contact comprises a base portion bent substantially in J-shape, a pair of plate-like contact pieces each having a conductive contact portion formed in the base portion and a terminal contact portion formed in the conductive contact portion, and a sheet-like electrical insulator disposed between both contact pieces. Accordingly, the contact has a three-layer structure with one contact piece, the electrical insulator and the other contact piece.
The contact is either is set at substantially the same thickness as or a little thicker than the width dimension of a plate-like terminal of a semiconductor device.
One of the two conductive contact portions is pressed against one conductive portion formed in a base plate, while the other of the conductive contact portions is pressed against the other conductive portion formed in the base plate. Both terminal contact portions are pressed against the terminal of the semiconductor device.
The contact is made to stand with its thickness direction oriented in the horizontal direction of the electrical connecting apparatus and is incorporated into the electrical connecting apparatus. At this time, the border between one contact piece and the electrical insulator as well as the border between the electrical insulator and the other contact piece extends in the extending direction of the terminal.
When inspecting the semiconductor device, the terminal of the semiconductor device is pressed against the terminal contact portion of the contact so that the extending direction of the terminal may coincide with the extending direction of the contact.
At this time, the terminal is positioned between one and the other of the contact pieces, and the border between the one contact piece and the electrical insulator as well as the border between the electrical insulator and the other contact piece extends in the extending direction of the terminal, so that one and the other terminal contact portions are brought into electrical contact with the right and left parts of the plate-like bottom face of the terminal.
Thereby, since one and the other contact pieces are electrically connected with one terminal, the electrical connecting apparatus and the semiconductor device can constitute a Kelvin connection.
However, when the connecting position of the terminal is displaced in the thickness direction of the contact, it is possible to electrically connect the terminal with the one contact piece, but it is sometimes not possible to electrically contact the terminal with the other contact piece.
In such a case, the terminal is electrically connected with one contact piece but not with the other contact piece. Accordingly, since the electrical connecting apparatus and the semiconductor device cannot constitute a Kelvin connection, the electrical connecting apparatus cannot conduct a Kelvin inspection of the semiconductor device.
Such a semiconductor device is judged as a defective product even if electrical characteristics are good. Therefore, a high dimensional tolerance is required for a semiconductor device and a terminal.